After years of delays and huge cost overruns, humanity’s next great space observatory, the James Webb Space Telescope, has successfully completed the final mission analysis review and is cleared for launch on or after October 31, 2021.
Peter Rumler, the European Space Agency (ESA) Webb project manager said “We are thrilled to have passed this important step towards the launch of Webb and to have received the green light from Arianespace and NASA.”
According to ESA “this major milestone, carried out with Arianespace, the Webb launch service provider, confirms that Ariane 5, the Webb spacecraft and the flight plan are set for launch. It also specifically provides the final confirmation that all aspects of the launch vehicle and spacecraft are fully compatible.”
The Webb telescope was originally proposed in 1996 as the Next Generation Space Telescope with an estimated cost in 1997 of US$500 million and a launch date of 2007. By 2002 the cost was estimated to be US$2.5 billion with a planned launch in 2009. Today, the total costs is estimated to be over US$10 billion.
Canadian contributions
The Webb telescope is an international partnership between ESA, NASA and the Canadian Space Agency. The Webb telescope is the largest and most powerful telescope to launch into space. Canada contributed the Fine Guidance Sensor and the Near-InfraRed Imager and Slitless Spectrograph (NIRISS) science instrument.
The Fine Guidance Sensor is critical in allowing the telescope to “see” and consists of two identical cameras that will guide the telescope’s position and locate its targets. The NIRISS science instrument will be particularly useful for exoplanet observation.
A delicate launch
For the launch of the Webb telescope modifications were needed on the Ariane 5. The “Ariane 5 has been customized to accommodate all the specific requirements of the Webb mission. New hardware ensures that venting ports around the base of the fairing remain fully open. This will minimize the shock of depressurisation when the fairing jettisons away from the launch vehicle.”
“Some elements of Webb are sensitive to radiation from the Sun and heating by the atmosphere. To protect it after the fairing is jettisoned, Ariane 5 will perform a specially developed rolling manoeuvre to avoid any fixed position of the telescope relative to the Sun. Additionally, an extra battery is installed on Ariane 5 to allow a boost to the upper stage after release of the telescope, distancing it from Webb.”
The Webb telescope will be launched to the Lagrange 2 point which is 1.5 million kilometres from Earth. It will take four weeks to reach its destination where it will reside in a stable orbit relative to Earth.
